Introduction
============
-The rfkill subsystem provides a generic interface to disabling any radio
+The rfkill subsystem provides a generic interface for disabling any radio
transmitter in the system. When a transmitter is blocked, it shall not
radiate any power.
* the rfkill drivers.
The rfkill core provides API for kernel drivers to register their radio
-transmitter with the kernel, methods for turning it on and off and, letting
+transmitter with the kernel, methods for turning it on and off, and letting
the system know about hardware-disabled states that may be implemented on
the device.
section below.
When the device is hard-blocked (either by a call to rfkill_set_hw_state()
-or from query_hw_block) set_block() will be invoked for additional software
+or from query_hw_block), set_block() will be invoked for additional software
block, but drivers can ignore the method call since they can use the return
value of the function rfkill_set_hw_state() to sync the software state
instead of keeping track of calls to set_block(). In fact, drivers should
Kernel API
==========
-
Drivers for radio transmitters normally implement an rfkill driver.
Platform drivers might implement input devices if the rfkill button is just
For some platforms, it is possible that the hardware state changes during
suspend/hibernation, in which case it will be necessary to update the rfkill
-core with the current state is at resume time.
+core with the current state at resume time.
To create an rfkill driver, driver's Kconfig needs to have::
depends on RFKILL || !RFKILL
to ensure the driver cannot be built-in when rfkill is modular. The !RFKILL
-case allows the driver to be built when rfkill is not configured, which
+case allows the driver to be built when rfkill is not configured, in which
case all rfkill API can still be used but will be provided by static inlines
which compile to almost nothing.
assign the poll_hw_block() callback (then the rfkill core will poll the
device). Don't do this unless you cannot get the event in any other way.
-RFKill provides per-switch LED triggers, which can be used to drive LEDs
+rfkill provides per-switch LED triggers, which can be used to drive LEDs
according to the switch state (LED_FULL when blocked, LED_OFF otherwise).
hotplugged devices.
After an application opens /dev/rfkill, it can read the current state of all
-devices. Changes can be either obtained by either polling the descriptor for
+devices. Changes can be obtained by either polling the descriptor for
hotplug or state change events or by listening for uevents emitted by the
rfkill core framework.
RFKILL_STATE
RFKILL_TYPE
-The contents of these variables corresponds to the "name", "state" and
+The content of these variables corresponds to the "name", "state" and
"type" sysfs files explained above.
-
For further details consult Documentation/ABI/stable/sysfs-class-rfkill.